Patent Document 1 describes a laser scanning device using a wavefront conversion element capable of arbitrarily converting the wavefront shape of light. This laser scanning device includes a light beam branching element provided within an optical path of a laser light beam, a beam expander, the wavefront conversion element, an objective lens for condensing light onto a sample plane, a photodetector, and a control device. The wavefront conversion element consists of a liquid crystal element configured such that its minutely divided respective regions can be independently controlled by the control device.